Rearrangements involving the long arm of chromosome 7 in uterine leiomyoma are widely recognized and comprise one of the major cytogenetic subgroups of these tumors. To approach a molecular genetic investigation of this subgroup for identification of a gene(s) involved in the biology of uterine leiomyomata we have analyzed breakpoints in the del(7q) subgroup in a series of myomas karyotyped in our laboratory. Herein we report the cytogenetic analysis of 11 uterine leiomyomata: eight with interstitial deletions in the long arm of chromosome 7 and three with translocations in 7q. These translocations provide further support for 7q22 as the critical band in the del(7q) subgroup.